¹The Vice Presidents formally serve as
presidents of the Senate, but rarely presides over routine
day-to-day debate. Until 1890, the Senate elected a
President Pro Tempore whenever
the Vice President was not in attendance. When the Vice
President returned, the President "Pro Tem" lost his
place, and when the Vice President was again absent, the Senate
again elected a President Pro Tempore.
By the standing order agreed to on 12 Mar 1890,
the Senate declared that the President Pro
Tempore shall hold office during "the pleasure
of the Senate and until another is elected, and shall
execute the duties thereof during
all future absences of the Vice President until the
Senate does otherwise order."

21 Jan
1903
Section of Militia Affairs within the Adjutant
General's office. 12 Feb
1908
Division of Militia Affairs within the War Department. 3 Jun
1916
Renamed Militia Bureau of the War Department. 15 Jun
1933
National Guard Bureau 1 Oct
1948
Made a Bureau of the Department of the Army and
an agency of the Department of the Air Force. 10 Jul
1959
Made a joint Bureau of the Departments of the
Army and Air Force.

12 Jun
1776
Board of War and Ordinance of the Continental Congress.
17 Oct
1777
Board of War 7 Feb
1781
War Office 7 Aug
1789
War Department created. 18 Sep
1947
War Department becomes the Department of the Army, a
branch of the Department of Defense.

¹The resolution of Congress on 10 Nov 1775
provided for a colonel to command two battalions of Marines authorized, but the
highest rank received by any Marine during the revolution was major. Samuel Nicholas
(s.a.) was appointed "Captain of Marines" on 28 Nov 1775, and promoted to major on 25 Jun 1776.
Because of his senior status among other Marine officers of the Revolution, he is
numbered as the first Commandant. The year 1781 saw Major Nicholas' return to
private life. By the summer of 1781 there were only three Marine captains and three
lieutenants on active duty, and the overall organization
had ceased to exist.

1 Aug
1907
Aeronautical Division established within the
U.S. Army Signal Corps. 18 Jul
1914
Renamed Army Aviation Section. 21 May
1918
Separated from Signal Corps and divided into the
Division of Military Aeronautics and the Bureau of
Aircraft Production. 27 Aug
1918
Reunified as the Army Air Service. 2 Jul
1926
Renamed Army Air Corps. 20 Jul
1941
Army Air Forces. 9 Feb
1942
Post of Chief of the Air Force Staff created. 18 Sep
1947
U.S. Air Force a separate branch of Department of
Defense.

20 Aug
1789
Secretaries of War responsible for American
Indian Affairs. 21 Apr 1806 - 6 May 1822 Office of
Indian Tradewithin Department of
War.
11 Mar
1824
Bureau of Indian Affairswithin
Department of War. 9 Jul
1832
Commissioner of Indian Affairs post established
(within the War Department). 29 Jul
1834
Office of Indian Affairs organized. 3 Mar
1849
Transferred to Department of the Interior.
17 Sep 1947
Renamed Bureau of Indian Affairs.

18 May 1796 - 1825
Post of Surveyor General of Northwest Territories
created.
25 Apr 1812
General Land Office (GLO) created (within
Department of Treasury).
3 Mar 1849
GLO transferred to the Department of
Interior.
28 Jun 1934
Division of Grazing created (within the
Department of Interior)26 Aug 1939
Division of Grazing renamed
U.S. Grazing Service.
16 Jul 1946
Bureau of Land Management (BLM)
formed by merger of Grazing Service
and
General Land Office (within Department
ofInterior).